1. Field of the Invention
The present invention relates to a process for preparing an optical recording medium. In particular, this invention relates to a process for preparing an optical recording medium with photochromic properties, which comprises a monomolecular film or a lamination of organic monomolecular films having polydiacetylenic bonds.
2. Description of the Prior Art
Diacetylene derivative polymers have conductivity and nonlinear optical effects because of the presence of a .pi.-electron conjugated system derived from polydiacetylenic bonds. Thus, these polymers are useful as optical- and electronic functional-materials such as optical recording media. For example, as in the form of thin film such as monomolecular film.
A thin polymer film that contains polydiacetylenic bonds is prepared by irradiating radioactive rays to a thin crystalline film of a diacetylene derivative compound. However, according to this process, a single crystalline polydiacetylene thin film of large size cannot be obtained. The film is also prepared by irradiating radioactive rays to a monomolecular film formed by the Langmuir-Blodgett (LB) technique on a base plate, resulting in polymerization of the diacetylene groups.
According to this process, a polydiacetylene derivative thin film of relatively large size can be obtained. However, the film prepared by this process has poor adhesiveness to the base plate. Thus, when the optical recording medium that contains this monomolecular film is worked, the film is susceptible to peeling from the base plate. Moreover, the process will be expensive from a practical point of view because it is less efficient. Also, the resulting optical recording medium has low density, and some pinholes.